I would encourage people to check out Fairlay.com. It's a BTC-only betting exchange with zero comms (for now). Right now, they have a market maker who clones Pinnacle exactly.
- Reduced juice and decent limits on everything.
- Tons of alternate lines are offered.
- Payouts and deposits are free and usually quick.
- Zero commission on sports.
- Potential for a true exchange down the road (right now, it's really only the MM making offers).
- No idea of the how well-funded the owners or their market marker are.
- Anononymity doesn't seem to be a priority (anyone with an API can apparently see which userid is betting a given game -- I have not confirmed this first-hand).
- The MM hits Pinnacle pretty hard in response to certain bet amounts/types/users.
- It appears to be run by a very small group of people.
- Interface needs work. It's esp. counter-intuitive for American-style odds. The site itself is also pretty sluggish.
- They tend to close games 2-3 min. before Pinnacle does.
This is def. a work in progress, but well worth using if you lack access to Pinnacle. If things break right, I think they could become a big player within 2-3 years.